[unreadable] The Family Investigation of Nephropathy of Diabetes (FIND) Study aims to localize genes for diabetic nephropathy (DN) using concordant and discordant sibpair analytical approach. As one participating center in the FIND study, we are enrolling Mexican American (MA) families with advanced DN probands and their diabetic siblings with and without nephropathy. The FIND Subproject Committee and the FIND Steering Committee have approved the study of diabetic retinopathy in the FIND population. The goal of the diabetic retinopathy subproject is to identify the genetic basis of diabetic retinopathy and to evaluate potential genetic links between DN and diabetic retinopathy. 3,375 subjects will be enrolled in the diabetic retinopathy study. To date, the total number of subjects enrolled in the retinopathy subproject is about 1,788 subjects. In this project, we propose to enroll additional probands and their diabetic siblings who participated in the FIND study at the San Antonio Center. The Specific Aims are: (1) to identify and enroll DN probands who participated in FIND and their diabetic siblings with or without nephropathy, (2) Phenotype enrolled subjects regarding diabetic retinopathy, and (3) Investigate the genetics of diabetic retinopathy among FIND subjects. A FIND family eligible for retinopathy will consist of a proband with advanced DN and at least one discordant sib pair (have T2DM only for at least 10 yrs) or concordant sib pair (have DM with nephropathy). All diabetic siblings of FIND probands will be eligible to enroll upon qualifying of a proband to the retinopathy study in order to complete the family. In the first year we will enroll 200 willing subjects located within San Antonio. In the second year, we will enroll the remaining subjects (n=130), but focus mainly on subjects located outside San Antonio, siblings with deceased probands and ill or unable to attend the study visit. A special focus will be directed to enroll genotyped subjects based on a list provided by the FIND coordinating center. Our study will complement both the FIND study and the retinopathy subproject in several ways. We will enroll and collect data on family members who are currently enrolled in FIND study, which will enhance our understanding of the clustering of both traits: diabetic retinopathy and nephropathy in the FIND families. Furthermore, enrolling additional subjects in the retinopathy study will increase sample size and statistical power related to multivariate and genetic linkage analysis of the retinopathy project. The identification of genes linked to diabetic eye disease and diabetic kidney disease should increase the knowledge about the risk for a given patient and help identify those for whom intensive preventive or therapeutic measures may be most beneficial. [unreadable] [unreadable]